Networking system

ABSTRACT

In a networking system including a plurality of nodes connected with each other by a communication network, each node includes an abnormality discrimination unit configured, when a cumulative consumption current at the time of processing the data received from other node is out of a range (of current values estimated in advance based on an event at the other node, to discriminate the other node as an abnormal. By the networking system, the abnormality of the nodes on the network may be detected with a simple configuration.

RELATED APPLICATIONS

The present application is a national phase of International ApplicationNumber PCT/JP2017/042198, filed Nov. 24, 2017, which claims priority toJapanese Application Number 2016-228825, filed Nov. 25, 2016.

TECHNICAL FIELD

The present invention relates to a networking system which is capable oftransmitting and receiving data between a plurality of nodes.

BACKGROUND ART

A technique described in Patent Document 1 below is known in the art,which relates to a networking system capable of transmitting andreceiving data between a plurality of nodes.

Patent Document 1 (Japanese Patent Laid-Open Publication No. 2010-20598)describes a network system in which nodes having data-driven processorsare connected with each other by an autonomously distributedcommunication network (ad hoc network), and data is transmitted andreceived.

PRIOR ART DOCUMENT Patent Document

[Patent Document 1] Japanese Patent Laid-open Publication No. 2010-20598

SUMMARY OF INVENTION Problems to be Solved by Invention

(Problems of the prior art) In the technique described in PatentDocument 1, when an abnormality such as a failure or an external attack(denial of service (DoS), etc.), a communication disabled state due toinfection with a computer virus, or adversely, transmission of a largeamount of data occurs in a certain node among the plurality of nodesexisting in the network, there is a problem that communication cannot beperformed between other nodes connected via the node in which theabnormality has occurred.

Further, in general, it is not possible for the node in which theabnormality has occurred to notify that an abnormality has occurred tothe outside by itself. The reason is that, the node in which theabnormality has occurred has entered a communication disabled state, orcannot notify that an abnormality has occurred due to the externalattack. Furthermore, the common ad hoc network as described in PatentDocument 1 is not provided with a structure configured to mutuallymonitor an abnormality of the nodes.

Therefore, when an abnormality occurs in a certain node on the network,there is a risk that the network cannot be maintained.

It is a technical object of the present invention to make it possible todetect an abnormality of nodes on a network with a simple configuration.

Means for Solving Problems

In order to solve the above technical object, according to a firstaspect of the present invention, there is provided a networking systemincluding a plurality of nodes connected with each other by acommunication network, wherein each node includes: a data-drivenprocessor including a self-synchronous pipeline (self-timed pipeline); apower circuit configured to supply a power to the data-driven processor;a consumption current detection unit configured to detect a consumptioncurrent in the data-driven processor; a reception unit configured toreceive data from other nodes; and an abnormality discrimination unitconfigured, when a cumulative consumption current at the time ofprocessing the data received from the other node is out of a range ofcurrent values estimated in advance based on an event at the other node,to discriminate the other node as abnormal.

A second aspect of the present invention is the networking systemaccording to the first aspect of the present invention, including a datadiscarding unit configured, when the reception unit receives data from anode discriminated as abnormal by the abnormality discrimination unit,to discard the received data, thus to isolate the node discriminated asabnormal from the network.

A third aspect of the present invention is the networking systemaccording to the first aspect of the present invention, wherein aconfiguration to transmit and receive information for a life-and-deathmonitoring of each node via the network to discriminate the abnormalityis not provided.

A fourth aspect of the present invention is the networking systemaccording to the first aspect of the present invention, including arange of current values estimated in advance based on a total amount ofthe events.

A fifth aspect of the present invention is the networking systemaccording to the first aspect of the present invention, including arange of current values estimated in advance based on a cycle of theevent.

Advantageous Effects

According to the first aspect of the present invention, the abnormalitydiscrimination unit of each node may mutually monitor whether anabnormality has occurred in each device by discriminating theabnormality of the other nodes, thus to detect the abnormality of thenodes on the network with a simple configuration. Further, according tothe first aspect of the present invention, by using the data-drivenprocessor having a strong correlation between the processing load andthe consumption current, it is possible to accurately discriminate theabnormality. Furthermore, according to the invention of the firstaspect, by discriminating whether the cumulative consumption current isout of the range of current values estimated in advance based on theevent at the other node, if the processing load is excessive orinsufficient, it may be determined as abnormal.

According to the second aspect of the present invention, by discardingthe data from the node in which the abnormality has occurred, it ispossible to substantially and automatically isolate the node in whichthe abnormality has occurred from the network.

According to the invention described in the third aspect, since theconfiguration for a life-and-death monitoring of each node is notprovided, it is possible to accurately discriminate the abnormality onlyby detecting the consumption current with no generation of processingload due to the configuration dedicated to the life-and-deathmonitoring.

According to the fourth aspect of the present invention, it is possibleto discriminate the abnormality when the cumulative consumption currentis out of the range of consumption current estimated depending on thetotal amount of events.

According to the fifth aspect of the present invention, it is possibleto discriminate an abnormality when the cumulative consumption currentis out of the range of consumption currents estimated depending on thecycle of the event.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an entire view describing a networking system provided with adata-driven processing apparatus of Embodiment 1 of the presentinvention.

FIG. 2 is a functional block diagram illustrating functions of thedata-driven processor of Embodiment 1.

FIG. 3 is a block diagram of an LSI in which the data-driven processorof Embodiment 1 is mounted, which is a diagram describing aself-synchronous elastic pipeline.

FIG. 4 is a graph illustrating a relationship between a processing loadand a consumption current of Embodiment 1.

FIGS. 5A and 5B are diagrams illustrating an example of the networkingsystem of Embodiment 1, wherein FIG. 5A is a diagram illustrating astate before an abnormal node occurs, and FIG. 5B is a diagramillustrating a case in which an abnormal node occurs.

MODE FOR CARRYING OUT INVENTION

Hereinafter, an embodiment which is a specific example of embodiments ofthe present invention will be described with reference to the drawings,but the present invention is not limited to the following embodiment.

Further, in the following description using the drawings, members otherthan members necessary for the description to facilitate theunderstanding will not be illustrated and described.

Embodiment 1

FIG. 1 is an entire view describing a networking system provided with adata-driven processing apparatus of Embodiment 1 of the presentinvention.

In FIG. 1, a networking system S of Embodiment 1 of the presentinvention includes a plurality of sensor nodes (nodes) N1 as an exampleof a data-driven processing apparatus. In addition, an automaticsecurity system device, a monitor (monitoring) device of a structuresuch as a water pipe or a gas pipe, a monitoring device of an elevatedbridge or a location where it is likely to cause mudslide, or amonitoring device of air pollutants and radiation, etc. may be appliedto the networking system S of Embodiment 1 as an example of the sensornode (node) N1. Further, the networking system S of Embodiment 1 mayalso be provided with a node (center node) N2 installed as an example ofthe data-driven processing apparatus at a center of a security company,a management company or a monitoring organization. Furthermore, inEmbodiment 1, unique identification information (node ID) is allocatedto each of the nodes N1 and N2.

Each node N1 has a data-driven processor 1 as an example of a processingunit. The data-driven processor 1 includes a firing control (FC) unit,an instruction fetch (IF) unit, an instruction decode (ID) unit, a dataprocessing unit (operation unit, execution (EX)), and a memory access(MA/write back (WB)) unit, etc., and is a conventionally known processorhaving a self-synchronous pipeline structure. The self-synchronouspipeline structure is disclosed, for example, in International PatentPublication No. 2013/011653, etc., and may employ variousconfigurations, therefore will not be described in detail.

The data-driven processor 1A is electrically connected with a wirelesscommunication module 2 as an example of a communication unit, a sensor 3as an example of a monitoring unit, and a display 4 as an example of adisplay member.

The wireless communication module 2 is configured to be able to transmitand receive data by wireless communication between other nodes N1. Inaddition, the wireless communication system of Embodiment 1 may employany configuration known in the art, and may employ a wireless LAN, amobile phone network, near field communication (NFC) or the like.Further, in Embodiment 1, it is possible to employ a sensor networkmethod as an example of an autonomously distributed communicationnetwork, or an ad hoc method. That is, a method of performing directcommunication between the nodes is employed, rather than performingcommunication between an access point governing the network and eachnode as an infrastructure method. Further, the communication network isnot limited to the autonomously distributed communication networkexemplified in the embodiment, and a wired communication network or acommunication network in which a path of communication is generalized(routed) as the infrastructure method.

In addition, the sensor 3 of Embodiment 1 includes, for example, anacceleration sensor, and senses and monitors vibrations of the node N1.Therefore, it is possible to detect vibrations when the node N1 isremoved or carried away from an installation site by theft or the like.Further, the acceleration sensor has been provided as an example of thesensor 3, but it is not limited thereto. For example, it is applicableto arbitrary sensors such as a sensor for a machine guard which detectshumans or animals as an example of an object to be monitored byelectromagnetic waves such as an infrared ray or visible light, or asensor for fire notification which detects smoke or heat of fire as anexample of the object to be monitored. Further, any member, to which asignal such as an image signal from a security camera, for example isinput, may be used. In addition, it is also applicable to sensors whichmonitor a public infrastructure and a private infrastructure for gasleakage of combustible gas or water leakage, for example, smart meterswhich remotely detect power consumptions in homes and offices,monitoring sensors for monitoring persons living alone, amachine-to-machine (M2M) sensor such as for detection of a sold-out orbreakdown state in a vending machine, and all sensors (sensing network)including techniques related to so-called internet of things (IoT),etc., in which things having communication functions are connected witheach other via the Internet to perform automatic recognition, automaticcontrol, remote measurement and the like.

In Embodiment 1, the data transmitted and received between therespective nodes N1 and N2 includes identification information (a nodeID) of the node N1 of a transmission source, identification information(a data ID) of the data, and a data body such as detection results ofthe sensor 3.

Further, the data-driven processor 1 of Embodiment 1 includes aso-called multi-core processor of a configuration having a plurality ofcores 1 a, 1 b, 1 c and . . . In Embodiment 1, processing is allocatedto each of the cores 1 a, 1 b, 1 c and . . . . For example, a first core1 a is set to perform processing of the detection results of the sensor3 in its own node N1, or distribution of the received data and the like.A second core 1 b is set to process data received from adjacent firstnodes N1 and N2, and a third core 1 c and a fourth core 1 d and . . .are set to process the data received from the adjacent second nodes N1and N2, and third nodes N1 and N2 and . . . .

FIG. 2 is a functional block diagram illustrating functions of thedata-driven processor of Embodiment 1.

In FIG. 2, the data-driven processor 1 of Embodiment 1 has the followingfunctional units (functional modules) 101 to 109. Further, in Embodiment1, the functional units 101 to 109 are provided for each core.

The power control unit 101 controls a voltage supplied to thedata-driven processor 1.

FIG. 3 is a block diagram of an LSI in which the data-driven processorof Embodiment 1 is mounted, which is a diagram describing aself-synchronous elastic pipeline.

In FIG. 3, the processor core 21 of the data-driven processor 1 ofEmbodiment 1 has a pipeline structure due to the self-synchronouselastic pipeline. The processor core 21 of Embodiment 1 has a pluralityof pipeline stages 51 corresponding to pipeline stages on functionalblocks (on architectures).

In FIG. 3, each pipeline stage 51 has a logic circuit (LC) 52 configuredto execute processing of each pipeline stage 51 based on a packettransmitted from an upstream pipeline stage 51 along the flow ofpackets, a data latch (DL) 53 connected to the logic circuit 52 to holdthe packet processed by the logic circuit 52, and a self-timed transfercontrol mechanism (STCM) 54 configured to supply a synchronizationsignal (clock signal, or trigger signal) to the data latch 53.

Further, the self-timed transfer control mechanism 54 of Embodiment 1 isconfigured similarly to the configuration described in Japanese PatentLaid-Open Publication No. 2010-20598, and has a coincidence element (Celement) 54 a as an example of a data transfer control circuit providedcorresponding to each data latch 53, and a delay element 54 b configuredto ensure a packet processing time in each logic circuit 52.Furthermore, operation and control of the self-timed transfer controlmechanism 54 of Embodiment 1 are known as described in Japanese PatentLaid-Open No. 2010-20598, and therefore will not be described in detail.

The logic circuit 52 and the data latch 53 are connected with a powersupply line 56 for supplying a drive voltage for driving the system. Thepower supply line 56 has a drive voltage line 56 a for supplying thedrive voltage (positive voltage, drain voltage, and drive power) Vddrequired when executing the processing in the logic circuit 52, and alowest voltage line 56 b for supplying the lowest voltage (minimumpower, power for holding data) Vmin of which is a voltage sufficient tohold packet data in the data latch 53 without executing the processingin the logic circuit 52 and lower than the drive voltage Vdd, and anegative voltage line 56 c for supplying a negative voltage (sourcevoltage, reference voltage, for example, ground: earth) Vss. Each of thevoltage lines 56 a to 56 c is provided with a power switch (PS) 56 d asan example of a switching element for switching a connection and adisconnection of voltage supply for each pipeline stage 51. That is, bycontrolling the power switch 56 d, it is possible to supply the drivevoltage Vdd and the minimum voltage Vmin to each of the logic circuits52 and the data latches 53, or turn off the voltage supply.

The power supply line 56 is connected with a power circuit 57 to supplythe respective voltages Vdd, Vmin, and Vss. Further, the power circuit57 is connected with a power control unit 101, and the drive voltage Vddis controlled to a variable voltage value by the power control unit 101.

Furthermore, in Embodiment 1, the data-driven processor 1 is configuredto be supplied with a power from a battery installed in the node N1, butthe power supply is not limited to the battery, and may employ any powersource such as an outlet or a rechargeable battery used in homes,offices and the like.

The power supply line 56 is connected with a galvanometer 58, and aconsumption current value Iss in the power supply line 56 is detected bya consumption current detection unit 102 via an analog-to-digitalconverter (ADC) (not illustrated). In addition, the power control unit101 increases or decreases a value of the drive voltage Vdd, inaccordance with the consumption current value Iss which increases ordecreases depending on the processing load of the data-driven processor1.

Furthermore, in Embodiment 1, the data-driven processor 1 (therespective control units 101 and 102), the power circuit 57, thegalvanometer 58, and the like are composed of one chip, but it is notlimited thereto. The data-driven processor 1 and the power circuit 57may also be composed of two or more separate chips.

FIG. 4 is a graph illustrating a relationship between the processingload and the consumption current of Embodiment 1.

If the consumption current value Iss detected by the consumption currentdetection unit 102 is out of the range of current values estimated inadvance, it is discriminated as an abnormal by an abnormalitydiscrimination unit 103.

In addition, the abnormality discrimination unit 103 of Embodiment 1discriminates whether a cumulative value of the consumption currentvalue Iss is out of the range of current values estimated in advance, onthe basis of the cumulative value of the consumption current value Issof a preset period based on a sufficient time required for measurementfrom a periodicity of a sensing object (a time enough not to be affectedby a fluctuation of the sensing results).

Although the event varies depending on the object sensed by each sensornode N1, for example, when the sensor node N1 detects a moving object asa human sensor, the detection of the object becomes an event, and whendetecting a sound, the detection of the sound becomes an event. Inaddition, for example, in a case of a sensor for detecting vibrations,the detection of the vibration becomes an event, and in a case of asensor for detecting a temperature, the detection of the temperaturebecomes an event. Then, when these events occur, power is consumedaccording to the processing, and the detection results are transmitted.Therefore, if a frequency of an occurrence of the events (a periodicityof the events) or the number of the events (a total amount of theevents) is increased, the consumption current is increased, and if thefrequency of an occurrence thereof is decreased, the consumption currentis decreased.

Then, by experiences of a manager and a user or by installing andmeasuring for a constant period of time, it is possible to estimate thefrequency and the number of occurrences of the events in each node N1,and it is also possible to estimate the range of consumption current.Therefore, when the sensor fails or an abnormality occurs in the sensingobject, an event does not occur at all, or adversely, events occur anabnormally large number of times, which cause a deviation from theestimated current value range.

Herein, the range of current values to be estimated may be estimated inadvance depending on, for example, a frequency of communication (anamount of packets transmitted and received within a fixed time). Inaddition, estimation is performed for each of the nodes N1 and N2depending on a sensitivity of sensing of the sensor node N1 (when thesensitivity is sensitive, the frequency of event detection isincreased). In addition, when the sensor node N1 is disposed at aposition where an object passing on time (such as a train) is detected(regularly and periodically detected), or in cases of the sensor node N1which regularly and periodically detects vibrations of a train or thelike, the sensor node N1 which detects a periodically occurring soundsuch as a clock bell, or the sensor node N1 which detects a temperaturechange that varies during the day or night, etc., estimation for each ofthe nodes N1 and N2 is performed depending on the periodicity and thetotal amount of the events.

Furthermore, a period of measuring the cumulative value of theconsumption current value Iss may be arbitrarily changed depending onthe sensing object, a specification or design of the network system, andthe like, but the period may be changed at any time or may beperiodically changed. Further, it also may be configured to measure achange in the cumulative value (profile) over time and discriminatewhether a slope of a curve of the profile, a width between peaks of amaximum value and a minimum value, etc. fall within the range estimatedin advance.

In FIG. 4, a range R1 of current values of Embodiment 1 is a range R1,in which a margin 62 is considered in a consumption current value 61corresponding to the processing load of the data-driven processor 1, isestimated in advance. Thereby, for example, since equipment of the nodeN1 falls, an earthquake occurs, etc., if the vibration (event) which isthe sensing object is increased, or the number of events is increased,the consumption current value Iss becomes a value exceeding the range R1of the current value.

In addition, when a signal is not input since the sensor 3 fails, theconsumption current value Iss becomes a value smaller than the range R1of the current value. Further, when the sensor 3 fails, if a signal suchas noise continues to be constantly input, the consumption current valueIss becomes a value exceeding the current value range R1.

Furthermore, when the data-driven processor 1 itself fails, the eventdoes not occur at all as described above, such that the current is notconsumed, or the same processing is repeated due to the runaway, suchthat the consumption current value Iss falls within the range R1 of thecurrent value.

Thereby, the abnormality discrimination unit 103 of Embodiment 1 maydetect an abnormality of the sensing object, an abnormality of thesensor 3, and an abnormality of the data-driven processor 1 itself fromthe abnormality of the consumption current value Iss. Further, theconsumption current value Iss has a high correlation with the processingload of the data-driven processor 1 and a high accuracy, as compared tothe case in which it is based on the amount of input packets. Thereby,the accuracy of detection of the abnormality of the sensor 3 or the likemay be easily improved.

Furthermore, the abnormality discrimination unit 103 of Embodiment 1discriminates that, when the processor core processes data from theother nodes N1 and N2, and if any one or all of the data-drivenprocessor 1, the wireless communication module 2, and the sensor 3 ofthe other nodes N1 and N2 fail, such that data is not received for along time (when the other nodes N1 and N2 are so-called “silent”), theconsumption current value Iss of the core is lower than the range R1.Adversely, when data is received more frequently than the frequencyestimated in advance due to a failure of other nodes N1 and N2 or anexternal attack, etc. (when the other nodes N1 and N2 are so-called“runaway”), the consumption current value Iss of the core exceeds therange R1. Therefore, it is also possible to discriminate an abnormality(failure, external attack, etc.) of the nodes N1 and N2 the processingof which is conducted by the core.

In FIG. 2, a reception unit 104 receives data transmitted (broadcasted)from the other nodes N1 and N2.

A reception history storage unit 105 stores a node ID and a data IDincluded in the data received by the reception unit 104.

An abnormal node storage unit 106 stores the nodes N1 and N2 which arediscriminated to be abnormal by the abnormality discrimination unit 103.The abnormal node storage unit 106 of Embodiment 1 stores the node ID ofthe node N1 discriminated to be abnormal.

An already-received discrimination unit 107 discriminates whether thedata received by the reception unit 104 is the same as the data alreadybroadcasted and received from the other node N1. From the node ID andthe data ID included in the received data, the already-receiveddiscrimination unit 107 of Embodiment 1 discriminates whether these dataare the data from the same transmission source as the already receiveddata (the node of a transmission source rather than a relay node).

When receiving the data from the node N1 discriminated to be abnormal, adata discarding unit 108 discards the received data. Further, the datadiscarding unit 108 of Embodiment 1 also discards the received data whenthe already-received data is received.

A broadcast unit 109, as an example of the transmission unit, broadcasts(transmits) the detection results (monitoring results) from the sensor 3to the neighboring nodes N1 and N2. That is, the data is transmitted,i.e., broadcasted to the nodes N1 and N2 present in the range in which aradio wave reaches from its own node N1. In addition, the broadcast unit109 transmits (so to speak, transfers or rebroadcasts) the data from theother nodes N1 and N2 in which no abnormality has occurred to theneighboring nodes N1 and N2.

FIGS. 5A and 5B are diagrams illustrating an example of the networkingsystem of Embodiment 1, wherein FIG. 5A is a diagram illustrating astate before an abnormal node occurs, and FIG. 5B is a diagramillustrating a case in which an abnormal node occurs.

In the networking system S of Embodiment 1 having the above-describedconfiguration, when receiving the data by its own nodes N1 and N2, thebroadcast unit 109 transmits (broadcasts) the received data to the otherneighboring nodes N1 and N2. In FIGS. 5A and 5B, as an example, anetwork having nodes N1 a to N1 g, and N2 may be considered. In FIG. 5A,when data is transmitted from a center node N2, there are cases in whichthe node N1 a directly receives the data broadcasted from the centernode N2, and receives the data which is received and rebroadcasted bythe node N1 b (relays the node N1 b). In Embodiment 1, when the node N1a receives data from the center node N2 first, and receives data thathas been relayed through the node N1 b later, the received data isdiscriminated by the already-received discrimination unit 107, anddiscarded by the data discarding unit 108. Therefore, duplicateprocessing of the same data is reduced in the node N1 a. Thereby, theprocessing load on each of the nodes N1 and N2 is reduced. In addition,since it is discarded when the same data is received, the data is notretransmitted from the node N1 a. Therefore, congestion on the networkis also reduced.

Accordingly, as illustrated by solid lines in FIG. 5A, in the respectivenodes N1 a to N1 g, the data from the node N2 is received andrebroadcasted (transferred) by each node N1 a to N1 g, such that thedata reaches all the nodes N1 a to N1 g. Further, as an example, FIGS.5A and 5B illustrate a state in which the data reaches first along apath illustrated by the solid lines and the data reaches later along apath illustrated by broken lines to be discarded.

Further, in the networking system S of Embodiment 1, each of the nodesN1 and N2 discriminates whether the neighboring nodes N1 and N2 areabnormal. That is, it is constituted that the nodes N1 and N2 includedin the network mutually monitor for the abnormality. Conventionally,there is no configuration in which the nodes N1 and N2 mutually monitorfor the abnormality. In the configuration in which sensors for detectingan abnormality are arranged in each node, when an abnormality occurs inthe communication module or the processor, data transmission itselfcannot be performed even when attempting to transmit the detectionresult of the abnormality. Thereby, there is a problem that costs areincreased if a sensor for detecting an abnormality is provided, or anetwork for communicating the abnormality detection result is separatelybuilt. On the other hand, in the networking system S of Embodiment 1,the abnormality of the other nodes N1 and N2 can be detected based onthe processing status of the communication data with the other nodes N1and N2. Therefore, the configuration may be simplified and the costs maybe reduced as compared to the case of providing the sensor for detectingan abnormality in the other nodes N1 and N2 their selves or building aseparate network.

In particular, in the networking system S of Embodiment 1, thedata-driven processor 1 is used. As described above, a correlationbetween the processing load of the data-driven processor 1 and theconsumption current is high and the accuracy is good. In a conventionalcommon Neumann-type processor, the load is measured by a program(software). In the conventional Neumann-type processor, it is necessaryto operate a program for observing the processing load, that is, forload measurement on a processor core which processes the received dataand the like. In other words, only the processing load of the processorcannot be observed from the outside. Thereby, the execution itself ofthe program for load measurement is an unpredictable load, and the loadat the time of execution cannot be accurately understood in advance.Therefore, the processing load and the consumption current are notalways in conjunction with each other (the correlation is low). Inaddition, since a load due to the execution of the program for loadmeasurement always occurs, it cannot be measured that the load is zero(or almost zero). Thereby, it is not possible to accurately detect thatother nodes have stopped due to a failure or the like (a life-and-deathmonitoring), and there is a problem that a configuration for alife-and-death monitoring is separately required.

For example, in the life-and-death monitoring (for example, PINGmonitoring), information (PING) on the life-and-death monitoring isperiodically transmitted and received, and the transmitted and receivedinformation is processed by software in each node (PING responseprocessing or life-and-death discrimination processing), thus to detectthe abnormality. Therefore, even in normal time, transmission andreception of the information for the life-and-death monitoring occur,and an overhead occurs for the original communication (transmission andreception of data other than the life-and-death monitoring) on thenetwork.

Further, in the conventional life-and-death monitoring, a CPU (hardware)and software are required to be operated (resources are required) inorder to discriminate an abnormality, and a load is generated. Thereby,the correlation between the consumption current and the processing loadis reduced. Therefore, in the conventional configuration, it isdifficult to discriminate the processing load only by observing theconsumption current. Further, as described above, since the abnormalitycannot be discriminated unless the CPU and the software are operating,there is also a problem that, if the CPU, the memory, and the like fail,or the software is runaway, the abnormality cannot be discriminated.

On the other hand, in the networking system S of Embodiment 1, thedata-driven processor 1 is used, and only by observing the consumptioncurrent having a high correlation with the processing load, it ispossible to discriminate an abnormality without requiring aconfiguration (software) dedicated to the life-and-death monitoring.

In addition, the abnormality discrimination unit 103 and the consumptioncurrent detection unit 102 may be provided outside the processor corewhich processes the received data and the like. Further, although theabnormality discrimination unit 103, etc. may be mounted by hardware, itis possible to achieve by software in a processor core dedicated toabnormality determination by providing the processor core dedicated toabnormality determination in a multiprocessor core configuration. Asdescribed above, in the conventional von-Neumann-type processor, it isnecessary to operate a program for load measurement (for life-and-deathmonitoring) on the processor core which processes the received data andthe like. Thereby, it is possible to observe the load from the outsidein the networking system S of Embodiment 1, which could not be achievedby the conventional Neumann processor.

Further, as described above, the conventional life-and-death monitoringis a configuration in which a query (PING) and its response data areexchanged on the network, and there is also a problem that an overheadoccurs for the original communication. However, in the networking systemS of Embodiment 1, the processing load of the data-driven processor 1may be observed from the outside of the data-driven processor 1 in eachof the nodes N1 and N2, and the overhead problem does not occur.Thereby, there is no necessity for software dedicated to thelife-and-death monitoring, which transmits and receives information forthe life-and-death monitoring via the network to discriminate anabnormality.

Further, in the networking system S of Embodiment 1, the datatransmitted from the nodes N1 and N2 discriminated to be abnormal isdiscarded (ignored). Therefore, the nodes N1 and N2 discriminated to beabnormal become substantially an isolation state from the network, so tospeak. Thereby, in the networking system S of Embodiment 1, therespective nodes N1 and N2 may mutually monitor whether there is noabnormality, and may automatically isolate the nodes N1 and N2 in whichthe abnormality has occurred from the network.

In FIGS. 5A and 5B, a case, in which an abnormality occurs in node N1 d,may be considered. When an abnormality occurs in the ode N1 d, the nodesN1 b, N1 c, N1 e, and N1 g, within a range in which radio waves from thenode N1 d may reach, detect the abnormality. Therefore, the receiveddata from node N1 d is discarded. Thereby, an adverse effect from thenode N1 d in which the abnormality has occurred is localized (theadverse effect is suppressed from spreading to the network).Accordingly, the node N1 d in which the abnormality has occurred becomesthe isolation state from the network, so to speak.

Further, in FIG. 5A, while the node N1 g receives the data broadcastedby the node N1 d in which the abnormality has occurred, if anabnormality occurs in the node N1 d, the data reaches the node N1 g vianodes N1 e and N1 f, as illustrated in FIG. 5B. Therefore, even if thenode N1 d in which the abnormality has occurred is isolated, the datamay reach the node N1 g, and the network may be maintained even with thenode N1 d in which the abnormality has occurred being isolated. Thereby,in the networking system S of Embodiment 1, even if an abnormalityoccurs in the node on a data transmission path, the data isautomatically transmitted and reaches along a bypass path, andredundancy is achieved in a good sense.

Further, in Embodiment 1, when an abnormality of the node N1 isdetected, it may be also configured to transmit data for notifying thecenter node N2 of the node in which the abnormality has occurred.

Modification

In the above description, the embodiment of the present invention hasbeen described in detail, but it is not limited to the above embodiment,and it is possible to perform various changes within the scope of thepurport of the present invention described in claims.

For example, the configuration, in which the consumption currentdetection unit 102 and the abnormality discrimination unit 103 areprovided in each of the processor cores 1 a, 1 b, 1 c and . . . , hasbeen exemplified, but it is not limited thereto. For example, it is alsopossible to configure in such a way that an abnormality is detectedbased on a total consumption current of the data-driven processor 1, andthen a location (its own node or other nodes) of the abnormality isspecified from the core subjected to excessive or insufficient packetprocessing after detecting the abnormality.

The configuration having the display 4 has been exemplified in the aboveembodiment, but it is not limited thereto, and a configuration withoutthe display is also possible. Further, in addition to the display 4 andthe wireless communication module 2, the node N1 may also be configuredto have an arbitrary member such as an actuator, a lamp, a buzzer or thelike.

In the above embodiment, the configuration, in which each sensor node N1includes the sensor 3 as an example of the monitoring unit, has beenexemplified, but it is not limited thereto. For example, it is alsopossible to apply the configuration of abnormality discrimination(mutual abnormality monitoring) and data discard (node isolation) of thepresent invention to a node that receives data from another node in thenetwork and transmits (transfers, rebroadcasts) the data to the othernodes without the sensor 3, i.e., to a so-called relay node. Inaddition, the configuration having both the reception unit and thetransmission unit has been exemplified, but it is not limited thereto.For example, a node such as a monitoring center may be configured as anode which only receives data transmitted from other sensor nodes N1without the broadcast unit (transmission unit), and it is also possibleto apply the configuration of abnormality discrimination and datadiscard of the present invention to this node.

In the above embodiment, the configuration, in which the abnormalitydiscrimination is performed based on the cumulative value of theconsumption current (temporal and/or profiled numerical value), has beenexemplified, but it is not limited thereto. For example, when the valueof the observed consumption current (so to speak, an instantaneousvalue) is excessive or insufficient, it is possible to discriminate asan abnormal. That is, if the consumption current value corresponding tothe processing load when receiving the data from the sensor 3 observingin each node N1 has no abnormality, and falling thereof within a certainrange is known through an experiment etc., it is also possible todiscriminate that an abnormality has occurred when exceeding the range.

1. A networking system comprising a plurality of nodes connected witheach other by a communication network, wherein each node comprises: adata-driven processor including a self-synchronous pipeline; a powercircuit configured to supply a power to the data-driven processor; aconsumption current detection unit configured to detect a consumptioncurrent in the data-driven processor; a reception unit configured toreceive data from other nodes; and an abnormality discrimination unitconfigured, when a cumulative consumption current at the time ofprocessing the data received from the other node is out of a range ofcurrent values estimated in advance based on an event at the other node,to discriminate the other node as abnormal.
 2. The networking systemaccording to claim 1, comprising a data discarding unit configured, whenthe reception unit receives data from a node discriminated as abnormalby the abnormality discrimination unit, to discard the received data,thus to isolate the node discriminated as abnormal from the network. 3.The networking system according to claim 1, wherein a configuration totransmit and receive information for a life-and-death monitoring of eachnode via the network to discriminate the abnormality is not provided. 4.The networking system according to claim 1, comprising a range ofcurrent values estimated in advance based on a total amount of theevents.
 5. The networking system according to claim 1, comprising arange of current values estimated in advance based on a cycle of theevent.